1. Field of the Invention
The present invention relates to card holders and particularly to card holders which can horizontally swivel when placed on a horizontal surface, such as a desk.
The invention also relates to swivel bases which can be attached to various devices to enable these devices to conveniently swivel when placed on horizontal surfaces.
2. Description of the Prior Art
Rotary card files have long been in use such as shown in U.S. Pat. Nos. 3,628,629 to Dahl, issued Dec. 21, 1971, entitled Magnetic Card Index; 3,260,006 to Dunajew, issued July 12, 1966, entitled Card Clip; and 2,731,966 to Neilsen, issued Jan. 24, 1956, entitled Rotary Card - Filing Device. Similarly, open type card files that are not rotary in nature have been shown as, for example, in Applicant's Design U.S. Pat. No. 251,848 to Hollerith, issued May 15, 1979.
All of these files are meant to be placed on desks or used in office locations where they are often moved about and become difficult to view. To facilitate the use of these devices to assist the viewer in viewing the contents, attempts have been made to provide means to swivel these files as, for example, in U.S. Pat. No. 4,035,938 to Neilsen, issued July 19, 1977, or Design Pat. No. Des. 280,423, issued Sept. 3, 1985, to Burton et al.
As can be seen from the Neilsen U.S. No. 4,035,938 and Burton U.S. Pat. No. Des. 280,423 patents, the swivel means are usually large and cumbersome. They must be large in order to stabilize the device and in doing so they also tend to elevate the device fairly high above the work surface, which tends to add instability to the device.